const promise = new Promise((resolve, reject) => {
    setTimeout(() => {  // 宏1
        console.log('timer');
        resolve('success');
    }, 1000);
});

const start = Date.now();

promise.then(res => {  // 微1
    console.log(res, Date.now()-start);
});

promise.then(res => {   // 微2
    console.log(res, Date.now()-start)
});

// timer -> success 时间1 -> success 时间2